Ahmed M. Montaser

B15. Tri-band slotted bow-tie antenna design for RFID reader using hybrid CFO-NM algorithm

In this article, a dual bow-tie slot antenna for 915/2450/5800 MHz triple band RFID applications is presented. The size of the proposed antenna is determined by the middle resonant frequency. The lower and upper operating frequencies are obtained by inserting metal strip pairs near the ends of the slotted dual bow-tie without increasing the overall antenna area. The hybrid approach involving Central Force Optimization and Nelder-Mead (CFO-NM) algorithm is considered to optimize the antenna dimensions. The CFO-NM algorithm program was implemented using MATLAB-software which linked to the CST Microwave studio software to simulate the antenna. In addition the optimized antenna is simulated by the Finite Difference Time Domain (FDTD) method to validate the results.

Tunable - compact bandstop defected ground structure (DGS) with lumped element

This paper introduces new compact DGS Resonators and an approach, in which lumped and tunable element are add within the DGS Resonating structure in certain places to obtain compact high performance and tunable filters. A comparison study of the combined resonators is presented to identify their relative advantages, disadvantages and their suitability for specific applications like cygnus system for seismic waves. A good agreement between the results of measurements and those produced from both the finite difference time domain method (FDTD) MATLAB code and the EM Simulation program are achieved.

Design Bluetooth and Notched-UWB E-Shape Antenna Using Optimization Techniques

In this article, an optimized E-shaped patch antenna for Bluetooth (2.4{2.484GHz) and UWB (3.1{10.6GHz) applications with WLAN (5.15{5.825GHz) band-notched characteristics is proposed. The dimensions of the E-shaped antenna structure in addition to the position of the slotted C-shape in the ground plane are optimized using recent optimization techniques such as Modifled Particle Swarm Optimization (MPSO), Bacterial Swarm Optimization (BSO), and Central Force Optimization (CFO). The optimization algorithms were implemented using MATLAB-software and linked to the CST Microwave Studio to simulate the antenna. Next, the efiects of the Laptop structure on the antenna radiation characteristics are considered. Finally, the antenna structures are simulated by the flnite difierence time domain method (FDTD) to validate the results. The measured results exhibit good agreement with the simulation from CST and the Finite Difierence Time Domain (FDTD) program written with matlab.

Slotted bow-tie antenna design for RFID readers using hybrid optimization techniques

Recently hybrid optimizations algorithm has attracted a lot of attention as a high-performance optimizer. This paper presents a comparison between different hybrid optimization algorithms. The proposed algorithms are used to design a slotted bow-tie antenna for 2.45 GHz Radio Frequency Identification (RFID) readers. The antenna is optimized using different algorithms integrated with the CST Microwave studio. Four algorithms are compared: Genetic Algorithm (GA), Particle Swarm Optimization (PSO), hybrid approach involving Genetic Algorithm (GA) and Nelder-Mead (NM) algorithm (GA-NM), and a hybrid approach involving PSO and Nelder-Mead optimization algorithm (PSO-NM). It is anticipated that the introduced hybrid approaches are more efficient and can be applied to other types of antennas.

Compact Ultra-Wideband monopole antenna design for wireless communication using differential evolution optimization algorithm

An internal Ultra-Wideband (UWB) monopole antenna for use in portable wireless communication applications is presented with a compact dimensions. It consists of a radiating patch, a matching stub, and a ground plane. The effect of defected ground plane structure (DGS) is studied in addition to the effect of defected slots in the radiating patch and matching stub on the return loss (S11). The Differential Evolution (DE) algorithm is considered to minimize S11 in the UWB frequency range by determining the appropriate antenna dimensions, the results are compared with other optimization techniques such as Genetic Algorithm (GA) and Particle Swarm Optimization (PSO). Also, the proposed antenna is built into a plastic case (εr = 3), having external dimensions 43.4 × 21.4 × 8.3 mm to study its effect on the radiation parameters.

B10. Design of A Compact Tri-band Antenna for RFID Handheld Applications using Optimization Techniques

In this article, the hybrid approach involving Central Force Optimization and Nelder-Mead (CFO-NM) algorithm is considered to optimize a compact dual bow-tie slot antenna for 915/2450/5800 MHz triple band RFID applications. The size of the proposed antenna is determined by the upper resonant frequency, and thus it is compact in nature. The middle and lower operating frequencies are obtained by inserting metal strip pairs near the ends of the slotted dual bow-tie without increasing the overall antenna area. The CFO-NM algorithm program was implemented using MATLAB-software which linked to the CST Microwave studio software to simulate the antenna. In addition the optimized antenna is assessed using the Finite Difference Time Domain (FDTD) program written with MATLAB to validate the results. Finally, the performance of the designed antenna in the presence of the human-hand model is investigated in addition to evaluating the spatial peak specific absorption rate (SAR).

B17. Planar inverted-F antenna array performance for smart handsets including the interaction with a human hand-head

In this paper the interaction of the planar inverted-F antenna array, mounted on a mobile handset, with a human hand-head phantom is investigatedin the 1.9 GHz band. The hybrid approach involving the particle swarm optimization (PSO) and Nelder-Mead (NM) algorithm is considered to optimize the complex excitations of the adaptive array elements in a mutual coupling environment for different beamforming synthesis. Firstly, the effect of the human hand-head on the handset radiation characteristics is studied. Then, the spatial peak specific absorption rate (SAR) values of 4-element antenna arrays for mobile handsets in the vicinity of a human hand-head are evaluated numerically for different scenarios. The antenna is analyzed completely using finite difference time domain (FDTD)while the interaction is performed using the CST Microwave Studio software.

Design a novel bandpass filter with microstrip resonator loaded capacitors using CFO-HC algorithm

This paper introduces a new way to reduce the length of a microstrip end-coupled resonator by loading its ends by a lumped capacitors. A new way of controlling the frequency of the 2nd harmonic even mode by loading the center of the resonator by a lumped capacitor directly or through less than 0.125 λgo part of a microstrip transmission line. Compact dual and triple modes bandpass filters with good selectivity are obtained. The length of transmission line section controls the phase and transforms the impedance of the capacitor which controls the bandwidth and generates transmission zeros. The transmission zeros can be located at upper or lower side of the passband by adjusting the loading capacitor values or the length of the transmission line. A second order bandpass filter with center frequency of 4 GHz is designed, fabricated and measured. The filter has a passband from 3.6 GHz to 4.4 GHz with a transmission zero at 4.8 GHz. The filter has good stopband performance with a rejection higher than 20 dB up to more than 10 GHz. Insertion loss of less than 0.75 is achieved within the passband. The measured results exhibit good agreement with the simulation one. An efficient global hybrid optimization method is proposed combining the Central Force Optimization (CFO) as a global optimizer and Hillclimbing (HC) algorithm as a local optimizer. After the final global iteration, a local optimization can be followed to further improve the solution obtained from the CFO. The hybrid Central Force Optimization and Hillclimbing (CFO-HC) algorithm is used to optimize the dimensions and values of the capacitance which contact them the filter, the (CFO-HC) algorithm was implemented using MATLAB-software and linked to the CST simulator to simulate the filter, In addition the optimized filter is simulated by the Finite Difference Time Domain (FDTD) program written with matlab to validate the results.